[WebAssembly] Use the correct size for MCFillFragment

[sunfish]

Summary

When implementing MCFillFragment, use the size of the fragment, rather than the size of the section.

[sbc100]

Can this land now? Its effecting a change that I'm working on.

[sunfish]

I'll get to this in a day or two, but feel free to land it yourself if you want it sooner :-).

llvm/trunk/lib/MC/WasmObjectWriter.cpp

if (WS.isFunction()) {
           // If nops are requested, use zeros, as this is the data section.
           uint8_t Value = Align->hasEmitNops() ? 0 : Align->getValue();
           uint64_t Size = std::min<uint64_t>(alignTo(DataBytes.size(),
                                                      Align->getAlignment()),
                                              DataBytes.size() +
                                                  Align->getMaxBytesToEmit());
           DataBytes.resize(Size, Value);
         } else if (auto *Fill = dyn_cast<MCFillFragment>(&Frag)) {
-          DataBytes.insert(DataBytes.end(), Size, Fill->getValue());
+          DataBytes.insert(DataBytes.end(), Fill->getSize(), Fill->getValue());
         } else {
           const auto &DataFrag = cast<MCDataFragment>(Frag);
           const SmallVectorImpl<char> &Contents = DataFrag.getContents();
 
           DataBytes.insert(DataBytes.end(), Contents.begin(), Contents.end());
         }
       }
 

llvm/trunk/test/MC/WebAssembly/array-fill.ll

+; RUN: llc -filetype=obj %s -o - | obj2yaml | FileCheck %s
+; PR33624
+
+source_filename = "ws.c"
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown-wasm"
+
+%struct.bd = type { i8 }
+
+@gBd = hidden global [2 x %struct.bd] [%struct.bd { i8 1 }, %struct.bd { i8 2 }], align 1
+
+; CHECK:  - Type:            DATA
+; CHECK:        Content:         '0102'
+; CHECK:    DataSize:        2